Activity Diagram - Nonlinear Process

An Activity Diagram is the UML diagram that provides a clear and logical way for you to display "how" your software application is going to work:

• Symbols used are intuitive, for easy explanation.
• A map of your application to follow control flow, show sequence of events and decisions occurring during execution.

Activity Diagram Symbols

We'll be introducing a new diagram symbol in this chapter.

Process As applications are made up of nested processes - both linear and nonlinear - this symbol, along with a descriptive name represents the start of each of those processes available to you in the application.

Activity Diagrams

Let's dive into an Activity Diagram for the Facebook app, which we've briefly outlined in a previous chapter. We've chosen (5) possible processes that are available to us in Facebook for the purpose of this example.

Pre-condition: Facebook application is open. Post-condition: Desired process/es are complete and the application closed.

You'll see above that these are (5) different options we have within the Facebook app. We've used the process symbol to illustrate, as each of these go into their own non-linear processes. Now we'll break down (2) of those processes into their own charts as you will be required to do on your own.

Below is the 1st process we'll pull out of our over arching nonlinear Facebook process, Share.

Above is what it would look like to diagram all (3) of the linear processes within "Share". Each end with the "Share" button being pressed but are not dependent on each other in order to execute the desired outcome.

Below is a breakdown of process 2 - Status Update.

As you can see, this time we've chosen (1) linear process within the nonlinear Status process to diagram. This process requires (2) steps and is independent of the other available options to the user.